1. Field of the Invention
The present invention relates to a method for image formation and an intermediate transfer recording medium for use in the same which, by forming an image in an object using the intermediate transfer recording medium to form a protective layer on the image, can easily prepare a print with no blank in the edge thereof, that is, the print having a whole picture plane with no blank.
2. Prior Art
Various thermal transfer methods have hitherto been known in the art. In these thermal transfer methods, a thermal transfer sheet comprising a color transfer layer provided on a substrate sheet is image-wise heated from its backside, for example, by means of a thermal head to thermally transfer the color transfer layer onto the surface of a thermal transfer image-receiving sheet, thereby forming an image. The thermal transfer methods are roughly classified according to the construction of the color transfer layer into two methods, i.e., sublimation dye thermal transfer (sublimation-type thermal transfer) and thermal ink transfer (heat-fusion-type thermal transfer). For both the methods, full-color images can be formed. For example, a thermal transfer sheet comprising layers of three colors of yellow, magenta, and cyan or optionally four colors of yellow, magenta, cyan, and black is provided, and images of the individual colors are thermally transferred in a superimposition manner on the surface of an identical thermal transfer image-receiving sheet to form a full-color image. The development of various hardwares and softwares associated with multimedia has led to the expansion of the market of the thermal transfer method as a full-color hard copy system for computer graphics, static images through satellite communication, digital images typified, for example, by images of CD-ROMs (compact disc read only memory), and analog images, such as video images.
Specific applications of the thermal transfer image-receiving sheet used in the thermal transfer method are various, and representative examples thereof include proofs of printing, output of images, output of plans and designs, for example, in CAD/CAM, output of various medical analytical instruments and measuring instruments, such as CT scans and endoscope cameras, alternative to instant photographs, output and printing of photograph-like images of a face or the like onto identity certifications or ID cards, credit cards, and other cards, and composite photographs and commemorative photographs, for example, in amusement facilities, such as amusement parks, game centers (amusement arcades), museums, and aquaria. The diversification of the applications has led to an increasing demand for the formation of a thermally transferred image on a desired object. One method proposed for meeting this demand comprises the steps: providing an intermediate transfer recording medium comprising a substrate and a receptive layer separably provided on the substrate; providing a thermal transfer sheet having a dye layer; transferring the dye from the thermal transfer sheet to the receptive layer in the intermediate transfer recording medium to form an image on the receptive layer; and then heating the intermediate transfer recording medium to transfer the receptive layer onto an object (see Japanese Patent Laid-Open No. 238791/1987).
When the thermal transfer images are formed for such these applications and an thermal transfer image is formed in an image-receiving sheet, a blank portion having no recording-image is usually formed around the image-receiving sheet, to prevent from smudging a platen for recording in a thermal transfer printer and smudging thermal transfer sheet with a colored transfer layer, or to carry a receiving sheet with such as a gripper, pinch roller and carrying roller.
Accordingly, for a receiving sheet of thermal transfer image, a print like a silver-salt picture which has recording image in a whole plane of an image-receiving sheet can not be prepared.
Accordingly, in order to solve the above problems of the prior art, it is an object of the present invention to provide an intermediate transfer recording medium and a method for image formation using the same which, by forming an whole plane image with no blank in transferred portion (patch portion) and retransferring the patch portion onto an object, can prepare an object having whole plane image with no blank in the edge of the print, and can yield a thermally transferred image possessing excellent various fastness properties even under severe service conditions.
Thus, the prevent invention provides A method for image formation, comprising the steps of: using an intermediate transfer recording medium comprising: a sheet substrate provided with a resin layer; and a transparent sheet provided with a receptive layer, the sheet substrate provided with the resin layer having been put on top of the transparent sheet provided with the receptive layer so that the transparent sheet faces the resin layer, forming a transfer image in said receptive layer, then retransferring the transfer image formed in said receptive layer onto an object, half-cutting said transparent sheet including the receptive layer, forming the transfer image in said receptive layer in an area equal to or larger than a whole area of the patch portion surrounded by the half cut, which is transferred when the transparent sheet including receptive layer is retransferred to the object, separating only the patch portion in the transparent sheet including the image-formed receptive layer from said resin layer, and retransferring the separated patch portion with no blank in the edge thereof onto the object. In this case, the print which has a whole image without flames can be prepared. In addition, since the transparent sheet as a protective sheet is provided onto an image of a print, a thermally transferred image which possesses excellent various fastness properties even under severe service conditions can be provided.
Further, in the embodiment of the present invention, the surface area of the patch portion is preferably smaller than or equal to the whole surface area of the portion transferred to the object. In this case, the patch portion does not project from the edge of the object.
The patch portion preferably has a partially removed portion relative to the object. According to this construction, for example, the position of a sign panel, an IC chip, or a magnetic stripe in the object, or the position of a design portion such as a logo or a hologram which has been previously printed on the object, can be registered with the partially removed portion followed by retransfer of the patch onto the object. In sign panel, IC chip, magnetic stripe and other portions, a deterioration in properties by post treatment of these portion can be prevented. In logo, hologram and other design portions, the formation of an image in these portions lowers the transparency, that is, increases opaqueness, and thus deteriorates the quality of the image. For this reason, the design portion is provided outside the image formation portion. The sign panel portion is a portion where handwriting with a writing instrument, such as a ballpoint pen, numbering with a stamp ink, and sealing with a vermilion inkpad are performed.
Further, Intermediate transfer recording medium of the prevent invention comprising the sheet substrate provided with the resin layer; and a transparent sheet provided with a receptive layer, the sheet substrate provided with the resin layer having been put on top of the transparent sheet provided with the receptive layer so that the transparent sheet faces the resin layer, said transfer image being formed in said receptive layer, said transparent sheet including the receptive layer being half-cut, said transfer image being formed in said receptive layer in an area equal to or larger than a whole area of the patch portion surrounded by the half cut, which is transferred when the transparent sheet including receptive layer is retransferred to the object, only said patch portion in the transparent sheet including the image-formed receptive layer being separated from said resin layer, and said separated patch portion with no blank in the edge thereof being retransferred onto the object.
Further, the total width of the intermediate transfer recording medium is preferably larger than the width of the object in its face on which the image is to be transferred. According to this construction, when an image is formed on the receptive layer in the intermediate transfer recording medium followed by the transfer of the image formation portion onto the object, direct contact of a heating device, such as a thermal head or a pressing roll, or a press plate, with the object can be avoided and, thus, damage to the object can be prevented.